Centre Européen de Recherche et d’Enseignement
des Géosciences de l’Environnement
Centre Européen de Recherche et d’Enseignement
des Géosciences de l’Environnement

Applications of the organic geochemistry unit

Molecular paleoclimatic indicators

The number of double bonds in the carbon chain of alkenones, molecules produced by phytoplankton coccolithophorids, depends on the temperature of the ocean surface water (unsaturation index UK37′). Similarly tetraether lipids (GDGTs) synthesised by archaea and bacteria allow the calculation of indices controlled by paleoclimatic factors (TEX86, MBT, CBT, RI-OH). The Organic Geochemistry Unit has successfully participated in international intercomparisons of analyses of these climate proxies measured by GC and GC-MS for alkenones (Rosell-Melé et al. 2001) and by HPLC-MS for tetraethers (Schouten et al. 2009). 

Since 1993, we have published numerous palaeotemperature series for sedimentary archives from marine and continental sites (Rostek et al. 1993, 1994, 1997, Bard et al. 1997, 1999, 2000, 2001, 2004, 2006, 2009, Sonzogni et al. 1997, 1998, Rosell-Melé et al. 1998, 2004, Cayre & Bard 1999, Pailler & Bard 2002, Sicre et al. 2002, Leduc et al. 2007, de Garidel-Thoron et al. 2007, Waelbroeck et al. 2009, Saher et al. 2009, Naughton et al. 2009, Vidal et al. 2010, Sepulcre et al. 2011, Soulet et al. 2011, Ménot & Bard 2012, Sanchez-Goni et al. 2013, Sanchi et al. 2013, 2014, Wegwerth et al. 2014, 2015, Darfeuil et al. 2016, Davtian et al. 2016, 2018, 2019, 2021, Martin et al. 2019, 2020, Rodriguez-Zorro et al, 2020, 2022).

In addition to palaeothermometry, molecular analyses provide information on many other environmental parameters. For example, sediment concentrations of alkenones, sterols and tetraethers are indicators of marine biological productivity (Rostek et al. 1994, 1997, Schulte et al. 1999, Budziak et al. 2000, Pailler and Bard 2002, Pailler et al. 2002, Schulte and Bard, 2003, Rickaby et al. 2007, Bard and Rickaby, 2009, Vidal et al., 2010). Freshwater inflow from melting icebergs and desalinated marine conditions are studied using tetra-unsaturated alkenones (Bard et al. 2000, Sicre et al. 2002, Ménot et al. 2006). Lycopane is a tracer of oxygenation conditions in the water column (Schulte et al. 1999) while diplopterol and diploptene are markers of the destabilisation of sedimentary methane hydrates (Ménot & Bard 2010).

In estuarine and continental margin sediments, the BIT and IIIa/IIa indices of GDGT tetraethers are linked to terrigenous fluvial inputs (Ménot et al. 2006, Soulet et al. 2013, Davtian et al. 2019, Ménot et al. 2020). Similarly, n-alkane and n-alkanone abundances are related to terrigenous inputs of plant material and their molecular ratios (ACL, CPI) provide information on plant types and organic matter preservation (Rostek & Bard 2013, Soulet et al. 2013, Shumilovskikh et al., 2016, Rodríguez-Zorro et al., 2020, Rodríguez-Zorro et al., 2022). Continental tetraethers are also markers of soil acidity (Sanchi et al. 2015, Davtian et al. 2016).

Molecular purification prior to 14C, 13C/12C and D/H isotopic analysis

We are developing a simple and robust method to purify alkenones by preparative liquid chromatography (Tool 8) prior to their age analysis 14C ion source with CO2 AixMICADAS gas analysis coupled with an elemental analyser. These organic molecules synthesised by plankton are commonly used in palaeothermometry and their dating 14C allows us to verify their origin and to better date the temperature records by comparing them with the dates 14C measured on carbonates (foraminifera). The method developed is based on the purification of the lipid extract by solid phase extractions followed by the separation and collection of the alkenones by HPLC-prep. The purity of the fractions is verified by HPLC-MS and by GC-FID and GC-MS. Other molecular compounds are being considered for dating certain alkenone-poor sediments. The same system is also used to purify alkenones prior to their isotopic analysis 13C/12C and D/H in the framework of the ANR Isobioclim project led by Guillaume Leduc.

Separation of hydroxyproline from collagen prior to radiocarbon dating

The HPLC-prep system (tool n°9) is mainly used in the laboratory to separate and isolate specific amino acids from collagen of archaeological bones in order to date them. Indeed, more accurate results can be obtained when radiocarbon dating is performed on specific molecules (amino acids) instead of materials as a whole (collagen). Of particular interest is hydroxyproline (HYP), which is one of the preponderant amino acids in collagen (Devièse et al. 2018). This molecular approach currently offers an excellent level of reliability that no other method can achieve, particularly in the case of highly contaminated samples (Devièse et al. 2021, Prüfer et al. 2021, Dinnis et al. 2021, Skov et al. 2022). It will be used in particular in the framework of the ANR NeHos project (From Neanderthals to Homo sapiens - Understanding a cultural (r)evolution in Europe during the Palaeolithic) led by Thibaut Devièse.

References for the organic geochemistry unit

2022

Rodríguez-Zorro PA, Ledru MP, Favier C, Bard E, Bicudo DC, Garcia M, Marquardt G, Rostek F, Sawakuchi AO, Simon Q, Tachikawa K, Alternate Atlantic forest and climate phases during the early Pleistocene 41 kyr cycles in southeastern Brazil, Quaternary Science Reviews 286, 107560, 1-15, DOI: 10.1016/j.quascirev.2022.107560 (2022).

Skov L, Peyrégne S, Popli D, Iasi LNM, Devièse T, Slon V, Zavala EI, Hajdinjak M, Sümer AP, Grote S, Bossoms Mesa A, López Herráez D, Nickel B, Nagel S, Richter J, Essel E, Gansauge M, Schmidt A Korlević P, Comeskey D, Derevianko AP, Kharevich A, Markin SV, Talamo S, Douka K, Krajcarz MT, Roberts RG, Higham T, Viola B, Krivoshapkin AI, Kolobova KA, Kelso J, Meyer M, Pääbo S, Peter BM. Genetic insights into the social organization of Neanderthals. Nature 610(7932): 519-525, DOI: 10.1038/s41586-022-05283-y (2022).

2021

Davtian N, Bard E, Darfeuil S, Ménot G, Rostek F. The novel hydroxylated tetraether index RI-OH′ as a sea surface temperature proxy for the 160-45 ka BP period off the Iberian Margin. Paleoceanography & Paleoclimatology 36, 1-34, e2020PA004077. DOI: 10.1029/2020PA004077 (2021).

Devièse T, Abrams G, Hajdinjak M, Pirson S, De Groote I, Di Modica K, Toussaint M, Fischer V, Comeskey D, Spindler L, Meyer M, Semal P, Higham T. Reevaluating the timing of Neanderthal disappearance in Northwest Europe. PNAS 118(12): e2022466118, DOI: 10.1073/pnas.2022466118 (2021).

Dinnis R, Bessudnov A, Reynolds N, Devièse T, Dudin A, Pate A, Sablin M, Sinitsyn A, Higham T. Eastern Europe's "Transitional Industry"? Deconstructing the Early Streletskian. Journal of Paleolithic Archaeology 4(1): 6, DOI: 10.1007/s41982-021-00076-7 (2021).

Prüfer K, Posth C, Yu H, Stoessel A, Spyrou MA, Deviese T, Mattonai M, Ribechini E, Higham T, Velemínský P, Brůžek J, Krause J. A genome sequence from a modern human skull over 45,000 years old from Zlatý kůň in Czechia. Nature Ecology & Evolution 5: 820-825, DOI: 10.1038/s41559-021-01443-x (2021).

2020 

Rodriguez-Zorro PA, Ledru MP, Bard E, Aquino-Alfonso O, Camejo A, Daniau AL, Favier C, Garcia M, Mineli TD, Rostek F, Sawakuchi A, Simon Q, Tachikawa K, Thouveny N. Shut down of the South American summer monsoon during the penultimate glacial. Scientific Reports 10: 6275, 1-11, + 18 p. suppl, DOI: 10.1038/s41598-020-62888-x (2020).

Martin C, Menot G, Thouveny N, Peyron O, Andrieu-Ponel V, Montade V, Davtian N, Reille M, Bard E. Early Holocene Thermal Maximum recorded by branchd tetraethers and pollen in Western Europe (Massif Central, France). Quaternary Science Reviews 228, 106109, 1-21, DOI: 10.1016/j.quascirev.2019.106109 (2020).

Ménot G, Pivot S, Bouloubassi I, Davtian N, Hennekam R, Bosch D, Ducassou E, Bard E, Migeon S, Revel M. Timing and stepwise transitions of the African Humid Period from geochemical proxies in the Nile deep-sea fan sediments Quaternary Science Reviews 228, 106071, 1-14, DOI: 10.1016/j.quascirev.2019.106071 (2020).

2019

Martin C, Ménot G, Thouveny N, Davtian N, Andrieu-Ponel V, Reille M, Bard E. Impact of human activities and vegetation changes on the tetraether sources in Lake St Front (Massif Central, France). Organic Geochemistry 135, 38-52, DOI: 10.1016/j.orggeochem.2019.06.005 (2019).

Davtian N, Ménot G, Fagault Y, Bard E. Western Mediterranean Sea paleothermometry over the last glacial cycle based on the novel RI-OH index. Paleoceanography and Paleoclimatology 34, 616-634, + 4 p. suppl, DOI: 10.1029/2018PA003452 (2019).

2018

Davtian N, Bard E, Ménot G, Fagault Y. The importance of mass accuracy in selected ion monitoring analysis of branched and isoprenoid tetraethers. Organic Geochemistry 118, 58-62, DOI: 10.1016/j.orggeochem.2018.01.007 (2018).

Devièse T, Comeskey D, McCullagh J, Bronk Ramsey C, Higham T. New protocol for compound-specific radiocarbon analysis of archaeological bones. Rapid Communications in Mass Spectrometry 32 (5), 373-379 (2018).

2017

Guerra L, Piovano EL, Córdoba FE, Tachikawa K, Rostek F, Garcia M, Bard E, Sylvestre S. Climate change evidences from the end of the Little Ice Age to the Current Warm Period recorded by Melincué Lake (Northern Pampas, Argentina). Quaternary International 438 (A), 160-174, DOI: 10.1016/j.quaint.2016.06.033 (2017).

2016

Shumilovskikh LS, Hopper K, Djamali M, Ponel P, Demory F, Rostek F, Tachikawa K, Bittmann F, Golyeva A, Guibal F, Talon B, Wang LC, Nezamabadi M, Bard E, Lahijani H, Nokandeh J, Rekavandi HO, de Beaulieu JL, Sauer S, Andrieu-Ponel V. Landscape evolution and agro-sylvo-pastoral activities on the Gorgan Plain (NE Iran) in the last 6000 years. The Holocene 26, 1676-1691, DOI: 10.1177/0959683616646841 (2016).

Davtian N, Ménot G, Bard E, Poulenard J, Podwojewski P. Considering soil types for the calibration of molecular proxies for soil pH and temperature. Organic Geochemistry 101, 140-153, DOI: 10.1016/j.orggeochem.2016.09.002 (2016).

Darfeuil S, Ménot G, Giraud X, Rostek F, Tachikawa K, Garcia M, Bard E. Sea surface temperature reconstructions over the last 70 kyr off Portugal: biomarker data and regional modeling. Paleoceanography and Paleoclimatology, 31, 40-65, + 15 p. suppl, DOI: 10.1002/2015PA002831 (2016).

2015

Wegwerth A, Ganopolski A, Ménot G, Kaiser J, Dellwig O, Bard E, Lamy F, Arz HW. Black Sea temperature response to glacial millennial-scale climate variability. Geophysical Research Letters 42, 8147-8154, DOI: 10.1002/2015GL065499 (2015).

Sanchi L, Ménot G, Bard E. Environmental controls on paleo pH at mid-latitudes: a case study from Central and Eastern Europe. Palaeogeography, Palaeoclimatology and Palaeoecology 417, 458-466, DOI: 10.1016/j.palaeo.2014.10.007 (2015).

2014

Wegwerth A, Dellwig O, Kaiser J, Ménot G, Bard E, Shumilovskikh L, Schnetger B, Kleinhanns IC, Wille M, Arz HW. Meltwater events and the Mediterranean reconnection at the Saalian-Eemian transition in the Black Sea. Earth and Planetary Science Letters 404, 124-135, DOI: 10.1016/j.epsl.2014.07.030 (2014).

Sanchi L, Ménot G, Bard E. Insights into continental temperatures in the northwestern Black Sea area during the last glacial period using branched tetraether lipids. Quaternary Science Reviews 84, 98-108, DOI: 10.1016/j.quascirev.2013.11.013, (2014).

2013

Bard E, Ménot G, Rostek F, Licari L, Böning P, Edwards RL, Cheng H, Wang YJ, Heaton TJ. Radiocarbon calibration/comparison records based on marine sediments from the Pakistan and Iberian Margins. Radiocarbon 55(4): 1999-2019, DOI: 10.2458/azu_js_rc.55.17114, (2013).

Rostek F, Bard E. Hydrological changes in Eastern Europe during the last 40,000 years inferred from biomarkers in Black Sea sediments. Quaternary Research 80, 502-509 DOI: 10.1016/j.yqres.2013.07.003, (2013).

Sanchez-Goni MF, Bard E, Landais A, Rossignol L, d'Errico F. Air-sea temperature decoupling in western Europe during the last interglacial-glacial transition. Nature Geoscience 6, 837-841, + 8 p. suppl, DOI: 10.1038/NGEO1924, (2013).

Soulet G, Ménot G, Bayon G, Rostek F, Ponzevera, Toucanne S, Lericolais G, Bard E. Abrupt drainage cycles of the Fennoscandian Ice sheet. Proceedings of the National Academy of Sciences 110 (17), 6682-6687, + 4 p. suppl. & 4 Tables, DOI: 10.1073/pnas.1214676110, (2013).

Sanchi L, Ménot G, Bard E. An automated purification method for archaeal and bacterial tetraethers in soils and sediments. Organic Geochemistry 54, 83-90, DOI: 10.1016/j.orggeochem.2012.10.005, (2013).

2012

Ménot G, Bard E. A precise search for drastic temperature shifts of the past 40,000 years in southeastern Europe. Paleoceanography 27, PA2210, 1-13, DOI:10.1029/2012PA002291, (2012).

2011

Soulet G, Ménot G, Garreta V, Rostek F, Lericolais G, Zaragosi S, Bard E. Black Sea "Lake" reservoir age evolution since the Late Glacial hydrologic and climatic implications. Earth and Planetary Science Letters 308, 245-258, DOI: 10.1016/j.epsl.2011.06.002 (2011).

Sepulcre S, Vidal L, Tachikawa K, Rostek F, Bard E. Sea-surface salinity variations in the Northern Caribbean Sea across the mid-Pleistocene transition. Climate of the Past 7, 75-90, DOI: 10.5194/cp-7-75-2011, (2011).

2010

Ménot G, Bard E. Geochemical evidence for a large methane release during the last deglaciation from Marmara Sea sediments. Geochimica et Cosmochimica Acta 74, 1537-1550, DOI: 10.1016/j.gca.2009.11.022, (2010).

Vidal L, Ménot G, Joly C, Bruneton H, Rostek F, Cagatay N, Major C, Bard E. Marmara Sea hydrology over the last 23000 years: implications for the connection with the Black Sea and the sapropel deposition. Paleoceanography 25, PA1205, 1-16, DOI: 10.1029/2009PA001735, (2010).

2009

Bard E, Rickaby R. Migration of the Subtropical Front as a modulator of glacial climate. Nature 406, 380-383 + 10 p. suppl., (2009).

Naughton F, Sanchez Goni M-F, Kageyama M, Bard E, Duprat J, Cortijo E, Malaizé B, Joly C, Rostek F, Turon J-L. Wet to dry climatic trend in northwestern Iberia within Heinrich events. Earth and Planetary Science Letters 284, 329-342, (2009).

Saher MH, Rostek F, Jung SJA, Bard E, Schneider RR, Greaves M, Ganssen GM, Elderfield H, Kroon D. Western Arabian Sea SST in the penultimate and last interglacial: a comparison of Uk'37 and Mg/Ca palaeothermometry Paleoceanography 24, PA2212, 1-12, DOI : 10.1029/2007PA001557, (2009).

Schouten S, Hopmans H, van der Meer J, Mets A, Bard E, Bianchi T, Diefendorf A, Escala M, Freeman KH, Huguet C, Ingalls A, Ménot G, Nederbragt AJ, Oba M, Pearson A, Pearson E, Rosell-Melé A, Schaeffer P, Smittenberg R, Talbot HM, Uchida M, van Moy B, Yamamoto M, Zhang Z, Sinninghe Damsté JS. An interlaboratory study of TEX86 and BIT analysis using high performance liquid chromatography/mass spectrometry. Geochemistry Geophysics Geosystems (G-cubed) 10, 1-13, DOI:10.1029/2008GC002221, (2009).

Waelbroeck C, Paul A, Kucera M, Rosell-Melé A, Weinelt M, Schneider R, Mix AC, Abelmann A, Armand L, Bard E, Barker S, Barrows TT, Benway H, Cacho I, Chen M-T, Cortijo E, Crosta X, de Vernal A, Dokken T, Duprat J, Elderfield H, Eynaud F, Gersonde R, Hayes A, Henry M, Hillaire-Marcel C, Huang C-C, Jansen E, Juggins S, Kallel N, Kiefer T, Kienast M, Labeyrie L, Leclaire H, Londeix L, Mangin S, Matthiessen J, Marret F, Meland M, Morey AE, Mulitza S, Pflaumann U, Pisias NG, Radi T, Rochon A, Rohling EJ, Sbaffi L, Schäfer-Neth C, Solignac S, Spero H, Tachikawa K, Turon JL. Constraints on the magnitude and patterns of ocean cooling at the Last Glacial Maximum. Nature Geoscience 2, 127-132, + 138 supplementary pages, DOI: 10.1038/NGEO411, (2009).

2008

Eris KK, Ryan WBF, Cagatay MN, Lericolais G, Sancar U, Menot G, Bard E. Reply to Comment on "the timing and evolution of the post-glacial transgression across the Sea of Marmara shelf, south of Istanbul" by Hiscott et al, Marine Geology 254, 230-236, (2008).

2007

Eris KK, Ryan WBF, Cagatay MN, Sancar U, Lericolais G, Menot G, Bard E, The timing and evolution of the post-glacial transgression across the Sea of Marmara shelf, south of Istanbul, Marine Geology 243, 57-76, (2007).

de Garidel-Thoron T, Rosenthal Y, Beaufort L, Bard E, Sonzogni C, Mix A, A multiproxy assessment of the equatorial Pacific hydrography during the last 30 ky. Paleoceanography 22, PA3204, 1-18, DOI:10.1029/2006PA001269, (2007).

Leduc G, Vidal L, Tachikawa K, Rostek F, Sonzogni C, Beaufort L, Bard E. Moisture transport across Central America as a positive feedback on abrupt climatic changes. Nature 445, 908-911 + 25 p. suppl. (2007).

Rickaby REM, Bard E, Sonzogni C, Rostek F, Beaufort L, Barker S, Rees G, Schrag D. Coccolith chemistry reveals secular variations in the global ocean carbon cycle ? Earth and Planetary Science Letters 253, 83-95, (2007).

2006

Ménot G, Bard E, Rostek F, Weijers JWH, Hopmans EC, Schouten S, Sinninghe Damsté JS. Early reactivation of European rivers during the last deglaciation. Science 313, 1623-1625 + 6 p. suppl. (2006).

Bard E, Rostek F, Ménot-Combes G. Chronology of rapid climatic variations during the last ice age. Comptes Rendus de l'Académie des Sciences (C.R. Palevol) 5, 13-19, (2006).

2004

Bard E, Ménot-Combes G, Rostek F. Present status of radiocarbon calibration and comparison records based on polynesian corals and Iberian Margin sediments. Radiocarbon 46, 1189-1203, (2004).

Bard E, Rostek F, Ménot-Combes G. Radiocarbon calibration beyond 20,000 B.P. by means of planktonic foraminifera of the Iberian Margin. Quaternary Research 61 (2), 204-214, (2004).

Rosell-Melé A, Bard E, Emeis KC, Grieger B, Hewitt C, Müller PJ, Schneider RR. Sea surface temperature glacial anomalies in the global ocean estimated from the alkenone UK37′ index: comparison with GCMs. Geophysical Research Letters 31, L03208, 1-4, (2004).

2003

Schulte S, Bard E. Past changes of biologically mediated dissolution of calcite above the chemical lysocline documented in Indian Ocean sediments. Quaternary Science Reviews 22, 1757-1770, (2003).

2002

Bard E, Delaygue G, Rostek F, Antonioli F, Silenzi S, Schrag DP. Hydrological conditions over the western Mediterranean basin during the deposition of the cold sapropel 6 event. Earth and Planetary Science Letters 202, 481-494 (2002).

Pailler D, Bard E. High frequency paleoceanographic changes during the past 140,000 years recorded by the organic matter in sediments off the Iberian Margin. Palaeogeography, Palaeoclimatology and Palaeoecology 181, 431-452, (2002).

Sicre M-A, Bard E, Ezat U, Rostek F. Alkenones distributions in the North Atlantic and Nordic sea surface waters. Geochemistry, Geophysics and Geosystems (G-cubed) 3 (2), 2001GC000159, 1-13, DOI: 10.1029/2001GC000159 (2002).

Pailler D, Bard E, Rostek F, Zheng Y, Mortlock R, van Geen A. Burial of redox-sensitive metals and organic matter in the equatorial Indian Ocean linked to precession. Geochimica et Cosmochimica Acta 66, 849-865, (2002).

2001

Rosell-Melé A, Bard E, Emeis K-C, Grimalt JO, Müller P, Schneider RR, Blanz T, Bouloubassi I, Epstein B, Fahl K, Fluegge A, Freeman K, Goni M, Güntner U, Hartz D, Hellebust S, Herbert T, Ikehara M, Ishiwatari R, Kawamura K, Kenig F, de Leeuw J, Lehman S, Mejanelle L, Ohkouchi N, Pancost RD, Pelejero C, Prahl F, Quinn J, Rontani J-F, Rostek F, Rullkötter J, Sachs J, Sawada K, Schulz-Bull D, Sikes E, Sonzogni C, Ternois Y, Versteegh G, Volkman J and Wakeham S. Precision of the current methods to measure the alkenone proxy UK37′ and absolute abundance in sediments: results of an interlaboratory comparison study. Geochemistry, Geophysics and Geosystems (G-cubed) 2, 2000GC000141, 1-28, (2001).

Bard E. Comparison of alkenone estimates with other temperature proxies. Geochemistry, Geophysics and Geosystems (G-cubed) 2, 2000GC000050, 1-12, (2001).

2000

Mix AC, Bard E, Eglinton G, Keigwin LD, Ravelo AC, Rosenthal Y. Alkenones and multi-proxy strategies in paleoceanographic studies. Geochemistry, Geophysics and Geosystems (G-cubed) 1, 2000GC000056, 1-22, (2000).

Bard E, Rostek F, Turon J-L, Gendreau S. Hydrological impact of Heinrich events in the subtropical northeast Atlantic. Science 289, 1321-1324 + 2 p. suppl. (2000).

Budziak D, Schneider R, Rostek F, Müller PJ, Bard E, Wefer G. Late Quaternary insolation forcing on total organic carbon and C37 alkenone variations in the Arabian Sea. Paleoceanography 15, 307-321, (2000).

1999

Cayre O, Bard E. The last deglaciation in the Eastern Arabian Sea: Planktonic foraminiferal and alkenone records. Quaternary Research 52, 337-342, (1999).

Schulte S, Rostek F, Bard E, Rullkötter J, Marchal O. Variations of oxygen-minimum and primary productivity recorded in sediments of the Arabian Sea. Earth and Planetary Science Letters 173, 205-221, (1999).

Bard E. Ice age temperatures and geochemistry. Science 284, 1133-1134, (1999).

1998

Rosell-Melé A, Bard E, Emeis KC, Farrimond P, Grimalt J, Müller PJ, Schneider RR. Project takes a new look at past sea surface temperatures. Eos Trans. of AGU 79 (33) 393-394, (1998).

Sonzogni C, Bard E, Rostek F. Tropical sea surface temperature during the last glacial period: a view based on alkenones in Indian Ocean. Quaternary Science Reviews 17, 1185-1201, (1998).

1997

Rostek F, Bard E, Beaufort L, Sonzogni C, Ganssen G. Sea surface temperature and productivity records for the past 240 kyr in the Arabian Sea. Deep Sea Research II 44, 1461-1480, (1997).

Sonzogni C, Bard E, Rostek F, Dollfus D, Rosell-Melé A, Eglinton G. Temperature and salinity effects on alkenone ratios measured in sediments from the Indian Ocean. Quaternary Research 47, 344-355, (1997).

Sonzogni C, Bard E, Rostek F, Lafont R, Rosell-Melé A, Eglinton G. Core-top calibration of the alkenone index versus sea surface temperature in the Indian Ocean. Deep Sea Research II 44, 1445-1460, (1997).

Bard E, Rostek F, Sonzogni C. Interhemispheric synchrony of the last deglaciation inferred from alkenone palaeothermometry. Nature 385, 707-710, (1997).

1994

Rostek F, Ruhland G, Bassinot F, Beaufort L, Müller PJ, Bard E. Fluctuations of the Indian monsoon regime during the last 170,000 years: evidence from sea surface temperature, salinity and organic carbon records. in Global Precipitations and Climate Change. M. Desbois & F. Désalmand (eds). NATO ASI Serie I, 26, 27-51, (1994).

1993

Rostek F, Ruhland G, Bassinot F, Müller PJ, Labeyrie L, Lancelot Y, Bard E. Reconstructing sea surface temperature and salinity using ∂18O and alkenone records. Nature 364, 319-321, (1993).